The Truth About Bone Health

While a fall may break your bones, so can inactivity, poor food choices, and even several seemingly healthy habits. Women as young as 30 are showing signs of bone loss, and up to 15% of premenopausal women have lost enough bone to qualify as osteopenic, meaning they are at increased risk for future fractures and hunched-over posture. To protect your skeletal health, it pays to get the lowdown on what's good—and what's not—for your bones.

Myth One: Osteoporosis doesn't run in my family, so I'm not at risk

FACT: Since about 98% of your bone mass is built by age 20, your past (rather than your genes) may give you a better glimpse at your future. If as a child you were active, a healthy weight, and ate many calcium-rich foods, you probably developed optimum bone mass. But if you were lax in bone-building behaviors and are still inactive, or you drink excessively, smoke, have lost weight rapidly, or have taken steroid medications for a long period of time, you may be at risk for brittle bones.

ACTION TO TAKE: The good news is that bone tissue remodels itself throughout life. At around age 40, cells that break down bone (particularly the spongy-looking inside of the bone that provides stability) become more active, while those that build bone slow down. But adopting healthy habits, like exercising regularly, eating right, losing weight gradually, and curbing alcohol and cigarette consumption, can still promote growth of your bones' strong outer shell and slow loss in the spongy part that is most prone to fracture.

Myth Two: Taking calcium supplements will prevent bone loss

FACT: "Women in the United States have among the highest calcium intake levels in the world, but they also have some of the highest rates of osteoporosis," says Walter Willett, M.D., a nutritional epidemiologist at Harvard School of Public Health. While many women take the recommended daily allowance (RDA) of calcium (1,000mg to 1,200mg), studies show that taking supplements alone doesn't necessarily improve bone density or fracture risk. "Calcium is essential, but it's probably the case that women need less calcium and more vitamin D, unless they are exposed to lots of sunlight," says Dr. Willett. (Vitamin D helps the body absorb calcium from the food we eat.) Plus, excess calcium (2,500mg or more per day) can interfere with bone repair because it prevents absorption of other nutrients, such as iron and zinc, that are also involved with bone formation. If you take a supplement, plus eat lots of dairy and calcium-fortified cereals or juices, you may be bordering on having too much.

ACTION TO TAKE: "Calcium pills are not mandatory, but a varied, healthy, fresh diet is," says Marion Nestle, Ph.D., a nutrition professor at New York University in Manhattan. Strive to meet your calcium needs through foods like kale, collard greens, broccoli, spinach, oranges, edamame, tofu, almonds, and sardines. Since studies show that 700 IU to 800 IU of vitamin D decreases fracture risk, find ways to include it in your diet as well (sources include egg yolks, D-fortified dairy products and O.J., canned tuna, and salmon). You can also meet your RDA by getting 10 to 15 minutes of sun three times a week. Eating plenty of fruits and vegetables will ensure you also take in other nutrients that play a role in bone health, including vitamins K and C, zinc, phosphorus, potassium, and magnesium.

Myth Three: The best way to get calcium is with dairy

FACT: There's little proof that dairy is an absolute must for strong bones, and some evidence indicates that too much dairy can even be harmful for certain people. "Some populations, like the Asians, eat little or no dairy and take in low levels of calcium through plant sources, yet they have strong bones and healthy teeth," says Dr. Willett. Up to two-thirds of the world's population is lactose intolerant—including around 50% to 90% of Mexican-Americans, African-Americans, Native Americans, and Asian-Americans. Those individuals can't consume much milk-based foods, yet they generally do not have higher rates of osteoporosis. Plus, some studies suggest a significant increased risk of some cancers in men and women who eat three or more servings of dairy a day, according to Dr. Willett. "This may be due in part to the fact that higher levels of calcium suppress a form of vitamin D that plays a role in limiting a cell's ability to keep multiplying."

Myth Four: My walking workouts are enough to stop bone loss

FACT: Muscle-toning exercises and low-impact activities such as walking and swimming are great for your health and overall strength, but they don't seem to provide enough stimulus to actually increase bone mass, says Miriam Nelson, Ph.D., an associate professor at the Friedman School of Nutrition Science and Policy at Tufts University in Boston. That's because bone-building cells need a sufficient amount of stress to be stimulated to do their thing. But the good news is that all that lower-impact activity does boost your coordination and balance, therefore decreasing your risk of falls—and fractures.

ACTION TO TAKE: All exercise is good for you. So keep up your weekly walks. But think about adding some moves that improve your balance to your routine. Standing on one leg or using a balance board is beneficial, says Nelson. And start jumping. Adding 10 minutes of jumping to your morning and evening routine (20 jumps with 30-seconds of rest in between) has been shown to improve bone density in women, says Larry Tucker, Ph.D., a professor in the department of exercise sciences at Brigham Young University, in Provo, Utah. You can also add impact with sports that require hitting a ball, such as volleyball or racquetball. Studies show that tennis players have greater bone density in their hitting arm. If you're new to exercise, you're likely to reap the biggest rewards: One study at Oregon State University in Corvallis found that women with low bone density who started a routine doing jumps and strength training had a two to five times greater improvement in bone density as a result of the one-year program than women who began the study with high bone density.

Warning Signs

Talk to your doctor about getting a bone scan if any of the below apply to you:

You suffered a bone fracture from a minor accident, such as falling from a standing height.

Your menstrual periods have stopped for no apparent reason or you haven't had a period for over a year.

You're at least 1 inch shorter than you used to be or your spine is progressively curving.

You're very thin or have a history of anorexia nervosa.

You get little sun and don't eat foods containing vitamin D.

How Strong Are Your Bones?

The gold standard for assessing bone mass is the dual energy X-ray absorptiometry, also known as the DEXA bone scan. This is a safe, painless X-ray that measures bone at different sites in the body, including the spine and hips. Your doctor may instead perform ultrasound scans of the heel, shin, or knee (called quantitative ultrasound or QUS). QUS measures the strength of bone in a certain area but doesn't assess overall bone density. A blood test can also estimate bone status by measuring levels of blood calcium. If the results of a bone scan suggest low bone mass, your doctor will help you plan the best bone-preserving strategy, which may include medications to slow down bone loss. Here are some common options.

BISPHOSPHONATES, such as alendronate (Fosamax), risedronate (Actonel), and ibandronate (Boniva), have been shown to reduce fractures.